Vegetable growers in the lower North Island may have lost up to 30 percent of their winter crops from the weekend flooding.
The industry body, Horticulture New Zealand, is still trying to build up a clear picture of the damage to market gardens and orchards.
Communications manager Leigh Catley said some vege growers in Horowhenua and Manawatu were reporting heavy losses.
"People are sill trying to get to grips with just how bad that's going to be," she said.
"Obviously, when you've got crops in the ground, sometimes you don't even know until you harvest just how much damage you've sustained, but I have heard suggestions of up to 30 percent losses in some areas.
"We're talking about green vegetables - cauliflower, cabbage, leeks, all sorts of things that you might see around at this time of year."
Ms Catley said that would reduce the quality and supply of some vegetables in the lower North Island and prices could be expected to rise as a result.
She said orchardists in the Whanganui area were also worried about the effect of flooding and silting on their trees and vines.
'There are little pockets of fruit-growing around Whanganui that have been affected and I know they were waiting with bated breath to go out and check their orchards," she said.
"There was a lot of water on the ground. There were orchards that were underwater at some stage and they were just waiting to see what sort of damage had been left once the water had receded.
"Things like silt build-up can be awfully hard on a kiwifruit vine, for instance."
Ms Catley said at least the kiwifruit harvest was finished before the floods hit.